i need advice

I don't think I'm attracted to my fiance anymore and we are supposed to get married in exactly 30 days. I'm terrified that we are going to get married and I'm going to regret it. we've been together for over a year and we dated for two years in highschool and right after we both graduated. I don't know if it's wedding nerves, changes in medications messing with my head, or if I'm just not attracted to him. i love him to death but it's just not there right now.